08e3abd414
If a network/subnet is deleted while creating the dhcp port, the agent will detect a conflict on state of the network and deal with it accordingly. A concurrent delete may manifest itself via a number of exceptions, IPAddressGenerationFailure amongst others, hence the refactoring of the error handling logic into its own utility method. Partial-bug: #1253344 Related-bug: #1243726 Change-Id: I442beb5f82f3db8786eea53926903ef0ba0efbf1